Special folders also apply to RootFolder unmapped folders

NzbDrone.Common/DirectoryLookupService.cs

@@ -35,8 +35,8 @@ namespace NzbDrone.Common
 
                     if (Path.GetPathRoot(path).Equals(path, StringComparison.InvariantCultureIgnoreCase))
                     {
-                        var setToRemove = new HashSet<string> { "$Recycle.Bin", "System Volume Information" };
-                        dirsList.RemoveAll(x => setToRemove.Contains(new DirectoryInfo(x).Name));
+                        var setToRemove = _diskProvider.SpecialFolders;
+                        dirsList.RemoveAll(x => setToRemove.Contains(new DirectoryInfo(x.ToLowerInvariant()).Name));
                     }
 
                     dirs = dirsList;

NzbDrone.Common/DiskProvider.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Runtime.InteropServices;
@@ -11,6 +12,7 @@ namespace NzbDrone.Common
 {
     public interface IDiskProvider
     {
+        HashSet<string> SpecialFolders { get; }
         DateTime GetLastFolderWrite(string path);
         DateTime GetLastFileWrite(string path);
         void EnsureFolder(string path);
@@ -36,7 +38,7 @@ namespace NzbDrone.Common
         void FolderSetLastWriteTimeUtc(string path, DateTime dateTime);
         bool IsFileLocked(FileInfo file);
         string GetPathRoot(string path);
-        void SetPermissions(string filename, string account, FileSystemRights Rights, AccessControlType ControlType);
+        void SetPermissions(string filename, string account, FileSystemRights rights, AccessControlType controlType);
         bool IsParent(string parentfolder, string subfolder);
         FileAttributes GetFileAttributes(string path);  
     }
@@ -58,6 +60,14 @@ namespace NzbDrone.Common
 
         private static readonly Logger Logger = LogManager.GetCurrentClassLogger();
 
+        public HashSet<string> SpecialFolders
+        {
+            get
+            {
+                return new HashSet<string> { "$recycle.bin", "system volume information", "recycler" };
+            }
+        }
+
         public DateTime GetLastFolderWrite(string path)
         {
             Ensure.That(() => path).IsValidPath();

NzbDrone.Core/RootFolders/RootFolderService.cs

@@ -99,7 +99,7 @@ namespace NzbDrone.Core.RootFolders
                 throw new ArgumentException("Invalid path provided", "path");
 
             var results = new List<UnmappedFolder>();
-            var series = _seriesRepository.All();
+            var series = _seriesRepository.All().ToList();
 
             if (!_diskProvider.FolderExists(path))
             {
@@ -116,6 +116,12 @@ namespace NzbDrone.Core.RootFolders
                 }
             }
 
+            if (Path.GetPathRoot(path).Equals(path, StringComparison.InvariantCultureIgnoreCase))
+            {
+                var setToRemove = _diskProvider.SpecialFolders;
+                results.RemoveAll(x => setToRemove.Contains(new DirectoryInfo(x.Path.ToLowerInvariant()).Name));
+            }
+
             Logger.Debug("{0} unmapped folders detected.", results.Count);
             return results;
         }